April 1, 1976Archives of Neurology
Reduced Plasma Norepinephrine Response to Standing in Autonomic Dysfunction
Why the study?
Does the plasma norepinephrine response to standing differ between patients with primary autonomic dysfunction and normal subjects?
Population
5 patients with primary autonomic dysfunction and clinical manifestations including postural hypotension…
Comparison
Standing position for 2 and 5 minutes vs Normal subjects
Design
Case-control
Follow-up
5 minutes
Authors
Discussion
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Implication
Blunted norepinephrine response may underlie postural hypotension in autonomic dysfunction; hypothesis-generating for diagnostic or prognostic utility.
Key Points
- To examine plasma norepinephrine and epinephrine responses to standing in patients with primary autonomic dysfunction presenting with postural hypotension.
- Assessed 5 patients with primary autonomic dysfunction and postural hypotension alongside a group of normal control subjects.
- Measured plasma norepinephrine and epinephrine concentrations after two and five minutes in the standing position.
- Mean (±SE) increment in plasma norepinephrine after two minutes of standing was 13 ± 4 pg/ml in patients versus 123 ± 19 pg/ml in normal subjects (P < .001).
- Mean increment in plasma norepinephrine after five minutes of standing remained lower in patients at 99 ± 51 pg/ml compared to 244 ± 36 pg/ml in normal subjects (P < .05).
- Plasma epinephrine concentrations showed no statistically significant differences between patients and normal controls.
Structured PICO
Does the plasma norepinephrine response to standing differ between patients with primary autonomic dysfunction and normal subjects?
P
Population
5 patients with primary autonomic dysfunction and clinical manifestations including postural hypotension, and normal subjects
I
Intervention
Standing position for 2 and 5 minutes
C
Comparator
Normal subjects
O
Outcome
Plasma norepinephrine concentration increment after 2 and 5 minutes standingsurrogate
Patients with primary autonomic dysfunction exhibit a significantly blunted plasma norepinephrine response to standing, which likely contributes to postural hypotension.
Cite This Study
Cryer et al. (1976) studied this question.